Thanks. I think you are saying the quote is FUDish? I would say it is and many of his posts are in the same vein, many of his "statements" are not about discussion. Many of his customers like that kind of positive simplistic statement of "fact"
Enter surreal territory here.
Magnetic Barkhausen Noise (MBN) signals are produced as a result of discrete changes in magnetisation caused mainly by the motion of the 180 degrees domain walls as the magnetic field is varied.
The important point is that the magnetic flux to be detected due to these discrete changes by the search coil of a Magnetic Barkhausen Noise search head is really tiny (at a level of 1E-15 Tesla/m2).
George
P.S. SQIDS are also being used as detectors of magnetic domain walls rotation.
The older methods utilized in proving the existence of discrete magnetic domains were: x-ray diffraction and optical methods (chemical etching and magneto-optical ellipsometry on prepared metallography specimens)
Sure, according to theory but in practice I find ferrite clamp-on filters can cause system distortion and also cause more subjectively noticeable noise......IME somehow these low level magnetic behaviours affect and effect systems enough to be audible and to be unpleasant/intrusive.
I have recorded such changes and the difference signal is 'gritty' sounding in addition to 'clanging' distortion signature.
I am by far not the first to note this problem with at least some ferrites, and my experience does not extend to all ferrite formulations so I do not make any blanket assertions.
There are plenty of opinions of permanent magnet formulation noise modulations also.
Dan.
No, I tried to say that using the term "FUD" for characterization of other peoples posts should have no place in a honest discussion.
If one complains about "simplistic stating of facts" (that descriptor might or not be warranted), he should refrain from shouting "FUD" as that is nothing else than a "negative simplistic statement of fact".
Isn't it better trying to find out what is meant and under which condition it is to perceive?
In a honest discussion there should be no FUD in the first place.
Sometimes it's necessary to call a spade a spade.
Understood (I think
)
It depends, amongst other things, whether it is his standard MO and part of the business plan. In the example quoted I would suggest, based on personal experience, it would be a complete waste of time
Not fear, but a little uncertainty and or doubt might be useful for helping steer back away from overconfidence bias.
Jakob, you asked me why I think there are errors in the article: Loudspeakers: Effects of amplifiers and cables - Part 5 | EE Times, by By Philip Newell and Keith Holland, published in EE times.
First set of measurements, shown as Figure 6.10 (a-f), shows “Effects of cable on 1.6 kHz square wave. All upper traces are from the amplifier output terminals; all lower traces are from the loudspeaker input terminals”.
I am missing measurements of the amplifier under test into various loads, resistive and complex. Square signal amplitude is about 50mV, cables used have length of 5m and 50m and the cables are a “coaxial cable”, a “parallel cable” and a “coaxial cable with screen as live”. It is said that “the measurements were taken in a city-centre office with typical city EMI”, without any further specification or measurements of the EMI fields. Considering “the city-centre office with typical city EMI” environment, I can say that according to my experience the induced interference voltage into a long “parallel cable” or a “ coaxial cable with screen as live” would be in tens of mVp-p with spectral components up to hundreds of MHz or units of GHz. If such content, with amplitude similar to a useful measured audio signal, is fed to the input of a digital spectrum analyzer (soundcard or a digital oscilloscope) without band-limiting filters that would restrict the measured signal to frequencies below Fs/2, both sound cards or digital oscilloscope spectrum analyzers do exhibit aliased spectral lines or intermodulation products. These are my main objections to the measurements seen in that article.
1) no measurements of amplifiers used, into complex load
2) the experiment is not described enough to show if proper anti-aliasing filters were used
The same objections to measurements in Figure 6.11.
Just to add, I have similar results if I do not use external anti-aliasing filters in front of the instrument for spectrum analysis.
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Yeah, it's a real giveaway that there is no desire for using dialogue to learn/ understand others viewpoint/ find some morsels of truth - just a rush to pigeonhole someone in a demeaning way & attempt to "win"
I let the whole McCarthyism of "are you or have you ever been Merrill Audio" play out as I saw it a prime example of just this type of tactic & would allow people to see who the perpetrators were.
I see it's still the same perpetrators doing it with "FUD", etc.
90% of the time it's an opinion, not a fact or "spade"
The distortion issue on reeds would never have been noticed, even Ed can't measure the third harmonic of 20fA.
We needed the off resistance of >10**15 Ohms.
I think that fear is more of a care for oneself, if not misguided. With FUD, the motivation is more external.
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